syntax/parse: remove unused field from rhs struct

racket/collects/syntax/parse/private/parse.rkt

@@ -114,7 +114,7 @@
  (define (rhs->parser name formals relsattrs the-rhs splicing?)
    (define-values (transparent? description variants defs commit? delimit-cut?)
      (match the-rhs
-       [(rhs _ transparent? description variants defs commit? delimit-cut? _)
+       [(rhs _ transparent? description variants defs commit? delimit-cut?)
         (values transparent? description variants defs commit? delimit-cut?)]))
    (define vdefss (map variant-definitions variants))
    (define formals* (rewrite-formals formals #'x #'rl))

racket/collects/syntax/parse/private/rep-data.rkt

@@ -24,7 +24,7 @@
 (define (stxclass/h? x)
   (and (stxclass? x) (stxclass-splicing? x)))
 
-;; An RHS is #s(rhs SAttrs Bool Stx/#f Variants Stxs Bool Bool Id/#f)
+;; An RHS is #s(rhs SAttrs Bool Stx/#f Variants Stxs Bool Bool)
 (define-struct rhs
   (attrs        ;; (Listof Sattr)
    transparent? ;; Bool
@@ -33,7 +33,6 @@
    definitions  ;; (Listof Stx), aux definitions from txlifts, local conventions?, etc
    commit?      ;; Bool
    delimit-cut? ;; Bool
-   pred         ;; ???
    ) #:prefab)
 
 #|

racket/collects/syntax/parse/private/rep.rkt

@@ -178,7 +178,7 @@
                   (intersect-sattrss (map variant-attrs variants)))])
          (make rhs sattrs transp? description variants
                (append (get-txlifts-as-definitions) defs)
-               commit? delimit-cut? #f))))))
+               commit? delimit-cut?))))))
 
 (define (parse-rhs/part1 stx splicing? strict?)
   (define-values (chunks rest)